Genetic susceptibility testing has been heralded as the future of personalized risk assessments and health care delivery. Genetic susceptibility feedback may be very useful for increasing the salience of health risks to young smokers who while acknowledging the health risks of smoking, are unrealistically optimistic about experiencing the harms of smoking. However, personalizing risk could prompt young smokers'to have cognitive and emotional reactions that could attenuate the potential for susceptibility feedback to motivate smoking cessation. The standard of care for genetic testing, a multi-step process interspersed with periods of waiting and anticipation, offers a framework for testing whether delivery of susceptibility feedback is related to defensive and optimistic information processing of susceptibility feedback. We examine whether these processes occur at two times: 1) during the waiting time in which results are unknown, and 2) upon receipt of the result. At both times, we posit that cognitive and emotional processes may influence defensive and optimistic reactions and, in turn, may affect risk perceptions and inclinations to quit smoking, To this end, proposed is a four-year prospective randomized trial. The overarching aim is to understand college smokers'cognitive and emotional responses to genetic susceptibility feedback (GSTM1) and their influence on downstream perceptions of lung cancer risks and worry and initial steps towards cessation. Proactively recruited students who consent to participate will be randomized in a 2:1 ratio to undergo genetic testing or to a wait list control group. Measures of cognitive and emotional reactions will be collected from students who agree to be tested at four time points: baseline, at the time of testing, immediately prior to and after receipt of the test result. Similar measures will be collected at each time point for those declining testing and the wait-list control group. The primary dependent variables collected after receipt of feedback are: perceptions of personal lung cancer risks and lung cancer worry. In addition, we will examine how several cognitive and emotional anticipatory factors (e.g., test expectation) assessed immediately prior to receipt of result, moderate initial reactions to test feedback (Aim 1). We further examine how the cognitive and emotional reactions (e.g. counter-arguing) to the test result mediate perceptions of lung cancer risks and worry (Aim 2).